This invention relates to a document copying system, and more particularly, to a copier that has improved means of detecting and removing jammed sheets therefrom.
Modern day copiers employ ever increasing processing speeds and depending upon the size and complexity of the xerographic machine and its operating speed, a number of record sheets may be in the transport path which includes the sheet feeding apparatus for delivering the record sheets from the input stack or paper supply through the transfer fixing stages to the output station. Particularly when a number of copies are to be made of each document original and the new copies are to be stored and assembled or collated into orderly groups, it is necessary that no record sheets be lost in the copying operation and that the same number of copies be made of each document original. As is known, due to variations in record media, for example, the stacking and orientation of paper in the paper output tray and malfunctions in the paper feed or sheet feed apparatus, it is possible for jams to periodically occur in the operation of the copying apparatus.
In prior art machines when a jam occurred, the operator stopped the machine, removed the damaged sheets in the transport path collecting the good sheets. These good sheets were then sorted by hand. The copying process was then continued. Particularly where each reproduction of the set of originals must be accurate, it is undesirable to have the operator manually distribute the good copies in the transport path during a mulfunction. Further, where the reproduction apparatus is high speed, it is undesirable to have the operator hold up and delay high speed operation while performing a manual operation. Further, during the slow or manual operator sorting, errors may occur in which a record sheet is either not fused or improperly reproduced thereby resulting in a faulty copy in a particular group or reproduced set.
The present invention is intended to overcome the above-mentioned disadvantages and comprises copy sheet jam sensing means and copy sheet cluster means located along the transport path of the copier actuated in response to copy sheet jams. Upon sensing a jam occurrence at a jam area, in-process copy sheets are clustered at a cluster area upstream of the sensed jam area in response to a downstream jam by continuing the operation of at least part of said transport path to said cluster area. The copy sheets at the jam area and the copy sheets clustered at the cluster area are then removed.